I never see a duet as having to be sung by one person to another .. simply that two people are singing and I can enjoy two voices working together, just as it could be performed by a chorus. Sometimes it enhances a song (as for me the making IACBTMN did on Bat3), but it would never detract as long as I like both the voices. I don't particularly like the extended introduction to the Pandora's Box version, and prefer the production of Meat's version over all.
So my vote will be Both Can Work if that goes up as an option.
A song I'd love Meat and Patti to cover would be "I Know Him So Well" from Chess. That is clearly written as a duet for two women, but could easily be performed by a man and a woman singing about their feelings about each other with some minor changes in my view. Another way a song can be performed differently
Caryl